Question

I have a form that give Fname and Lname and Date and a method to write this information to a file.

If Fname or Lname contain digit, the program should display an error message and not run all below statements ,(like write to file and generate random number and…), and not exit.
since i dont know how to do like this, in my code i write if Fname or Lname have digit, exit !

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt)   {                                         
    try{
        setFName(jTextField1.getText());
        if(havedigit(getFName())==true) { 
            System.exit(1);
        }
        setLName(jTextField2.getText());
        if(havedigit(lastName)==true) {
            System.exit(1);
        }
        WriteToFile(getFName());
        WriteToFile(getLName());
        setDate(Integer.parseInt(jTextField3.getText()));
        WriteToFile(String.valueOf(getDate()));
        Random rnd1=new Random();
        Registration_Number=rnd1.nextInt(100);
        setRegNum(Registration_Number);
        WriteToFile(String.valueOf(getRegNum()));
        jLabel6.setText(String.valueOf(getRegNum()));
    }
    catch(Exception e){
        jLabel6.setText("Error!");
    }
}                                        

public boolean havedigit(String in){
    for(int i=0;i<in.length();i++){
        if(Character.isDigit(in.charAt(i)))  return true;
    }
    return false;
}

please help!

Answer 1

Here’s one way you could do it:

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt)   {                                         

    try{
        setFName(jTextField1.getText());
        setLName(jTextField2.getText());
        boolean firstNameHasDigit = havedigit(getFName());
        boolean lastNameHasDigit = havedigit(getLName());
        if (firstNameHasDigit || lastNameHasDigit) {
            jLabel6.setText("Names cannot contain digits");
        }
        else {
            WriteToFile(getFName());
            WriteToFile(getLName());
            setDate(Integer.parseInt(jTextField3.getText()));
            WriteToFile(String.valueOf(getDate()));
            Random rnd1=new Random();
            Registration_Number=rnd1.nextInt(100);
            setRegNum(Registration_Number);
            WriteToFile(String.valueOf(getRegNum()));
            jLabel6.setText(String.valueOf(getRegNum()));
        }
    }
    catch(Exception e){
        jLabel6.setText("Error!");
    }
}                                        

public boolean havedigit(String in){
    for(int i=0;i<in.length();i++){
        if(Character.isDigit(in.charAt(i)))  return true;
    }
    return false;
}